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import PIL, math
#Problem 14 Longest Collatz sequence
#Note, a little slow, takes about 15 seconds.
#There is probably a more efficient solution out there
chain = []
biggo = []
def collatz(seed):
chain.append(seed)
if(seed == 1): return 0
if(seed%2 == 0):
seed = seed/2
else:
seed = 3*seed +1
collatz(seed)
for n in range(1,pow(10,6)):
collatz(n)
if(len(chain)>len(biggo)):
biggo = chain
chain = []
print(biggo)
print("Has " + str(len(biggo)) +" numbers.")
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